Various embodiments relate to LED modules having a plurality of LEDs which are connected in series. This applies in particular to linear and planar LED modules. The operating voltage of the LED module is determined by the number of LEDs connected in series.
By way of example, safety extra low voltages (SELV), which are handlable particularly simply, or higher low-voltage ranges (e.g. 70-110 V, designated hereinafter generally as HV), in which particularly efficient power supply units can be designed, are known as advantageous operating voltage ranges for LED modules of this type. One voltage range or the other may be advantageous depending on requirements in respect of the handlability and the efficiency of the LED modules.
In accordance with the prior art, therefore, different LED modules are designed for the different voltage ranges. What is disadvantageous in this case is that different LED modules have to be conceived, constructed and kept in stock.
Furthermore, it is known to design LED modules for the SELV range and to operate a plurality of them in parallel, such that the requirement in respect of the operating voltage does not increase. Alternatively, e.g. two modules conceived for the SELV range are connected in series, and so their total supply voltage lies in the HV range as a result.
What is disadvantageous in this case is that at least two LED modules are required, and that the total number of modules has to be even.
Furthermore, the prior art discloses LED modules which contain a switching logic (e.g. double changeover switch), in order to interconnect LED partial chains of the module either in parallel or in series, such that the module can be operated with parallel-connected partial chains in the SELV range and with series-connected partial chains in the HV range. What is disadvantageous in this case is that the changeover switch requires structural space and causes costs.